source: rtems/c/src/exec/libnetworking/libc/res_init.c @ ff0f694d

4.104.114.84.95
Last change on this file since ff0f694d was ff0f694d, checked in by Joel Sherrill <joel.sherrill@…>, on 08/20/98 at 21:47:37

Fixed many warnings.

  • Property mode set to 100644
File size: 15.2 KB
Line 
1/*
2 * Copyright (c) 1985, 1989, 1993
3 *    The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by the University of
16 *      California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34/*
35 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
36 *
37 * Permission to use, copy, modify, and distribute this software for any
38 * purpose with or without fee is hereby granted, provided that the above
39 * copyright notice and this permission notice appear in all copies, and that
40 * the name of Digital Equipment Corporation not be used in advertising or
41 * publicity pertaining to distribution of the document or software without
42 * specific, written prior permission.
43 *
44 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
47 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51 * SOFTWARE.
52 */
53
54/*
55 * Portions Copyright (c) 1996 by Internet Software Consortium.
56 *
57 * Permission to use, copy, modify, and distribute this software for any
58 * purpose with or without fee is hereby granted, provided that the above
59 * copyright notice and this permission notice appear in all copies.
60 *
61 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
62 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
63 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
64 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
65 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
66 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
67 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
68 * SOFTWARE.
69 */
70
71#if defined(LIBC_SCCS) && !defined(lint)
72static char sccsid[] = "@(#)res_init.c  8.1 (Berkeley) 6/7/93";
73static char orig_rcsid[] = "From: Id: res_init.c,v 8.7 1996/11/18 09:10:04 vixie Exp $";
74static char rcsid[] = "$Id$";
75#endif /* LIBC_SCCS and not lint */
76
77#include <sys/types.h>
78#include <sys/param.h>
79#include <sys/socket.h>
80#include <sys/time.h>
81#include <netinet/in.h>
82#include <arpa/inet.h>
83#include <arpa/nameser.h>
84#include <ctype.h>
85#include <resolv.h>
86#include <stdio.h>
87#include <stdlib.h>
88#include <string.h>
89#include <unistd.h>
90
91#include "res_config.h"
92
93static void res_setoptions __P((char *, char *));
94
95#ifdef RESOLVSORT
96static const char sort_mask[] = "/&";
97#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
98static u_int32_t net_mask __P((struct in_addr));
99#endif
100
101#if !defined(isascii) /* XXX - could be a function */
102# define isascii(c) (!(c & 0200))
103#endif
104
105/*
106 * Resolver state default settings.
107 */
108
109struct __res_state _res
110# if defined(__BIND_RES_TEXT)
111        = { RES_TIMEOUT, }      /* Motorola, et al. */
112# endif
113        ;
114
115
116/*
117 * Set up default settings.  If the configuration file exist, the values
118 * there will have precedence.  Otherwise, the server address is set to
119 * INADDR_ANY and the default domain name comes from the gethostname().
120 *
121 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
122 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
123 * since it was noted that INADDR_ANY actually meant ``the first interface
124 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
125 * it had to be "up" in order for you to reach your own name server.  It
126 * was later decided that since the recommended practice is to always
127 * install local static routes through 127.0.0.1 for all your network
128 * interfaces, that we could solve this problem without a code change.
129 *
130 * The configuration file should always be used, since it is the only way
131 * to specify a default domain.  If you are running a server on your local
132 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
133 * in the configuration file.
134 *
135 * Return 0 if completes successfully, -1 on error
136 */
137int
138res_init()
139{
140        register FILE *fp;
141        register char *cp, **pp;
142        register int n;
143        char buf[MAXDNAME];
144        int nserv = 0;    /* number of nameserver records read from file */
145        int haveenv = 0;
146        int havesearch = 0;
147#ifdef RESOLVSORT
148        int nsort = 0;
149        char *net;
150#endif
151#ifndef RFC1535
152        int dots;
153#endif
154
155        /*
156         * These three fields used to be statically initialized.  This made
157         * it hard to use this code in a shared library.  It is necessary,
158         * now that we're doing dynamic initialization here, that we preserve
159         * the old semantics: if an application modifies one of these three
160         * fields of _res before res_init() is called, res_init() will not
161         * alter them.  Of course, if an application is setting them to
162         * _zero_ before calling res_init(), hoping to override what used
163         * to be the static default, we can't detect it and unexpected results
164         * will follow.  Zero for any of these fields would make no sense,
165         * so one can safely assume that the applications were already getting
166         * unexpected results.
167         *
168         * _res.options is tricky since some apps were known to diddle the bits
169         * before res_init() was first called. We can't replicate that semantic
170         * with dynamic initialization (they may have turned bits off that are
171         * set in RES_DEFAULT).  Our solution is to declare such applications
172         * "broken".  They could fool us by setting RES_INIT but none do (yet).
173         */
174        if (!_res.retrans)
175                _res.retrans = RES_TIMEOUT;
176        if (!_res.retry)
177                _res.retry = 4;
178        if (!(_res.options & RES_INIT))
179                _res.options = RES_DEFAULT;
180
181        /*
182         * This one used to initialize implicitly to zero, so unless the app
183         * has set it to something in particular, we can randomize it now.
184         */
185        if (!_res.id)
186                _res.id = res_randomid();
187
188#ifdef USELOOPBACK
189        _res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
190#else
191        _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
192#endif
193        _res.nsaddr.sin_family = AF_INET;
194        _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
195        _res.nscount = 1;
196        _res.ndots = 1;
197        _res.pfcode = 0;
198
199        /*
200         * RTEMS -- Set up name servers
201         */
202        {
203#include <rtems/rtems_bsdnet_internal.h>
204        int n = 0;
205        while ((n < rtems_bsdnet_nameserver_count) && (nserv < MAXNS)) {
206                _res.nsaddr_list[nserv].sin_addr = rtems_bsdnet_nameserver[n];
207                _res.nsaddr_list[nserv].sin_family = AF_INET;
208                _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT);
209                nserv++;
210                n++;
211        }
212        if (rtems_bsdnet_domain_name)
213                (void)strncpy(_res.defdname, rtems_bsdnet_domain_name, sizeof(_res.defdname) - 1);
214        }
215
216        /* Allow user to override the local domain definition */
217        if ((cp = getenv("LOCALDOMAIN")) != NULL) {
218                (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
219                haveenv++;
220
221                /*
222                 * Set search list to be blank-separated strings
223                 * from rest of env value.  Permits users of LOCALDOMAIN
224                 * to still have a search list, and anyone to set the
225                 * one that they want to use as an individual (even more
226                 * important now that the rfc1535 stuff restricts searches)
227                 */
228                cp = _res.defdname;
229                pp = _res.dnsrch;
230                *pp++ = cp;
231                for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
232                        if (*cp == '\n')        /* silly backwards compat */
233                                break;
234                        else if (*cp == ' ' || *cp == '\t') {
235                                *cp = 0;
236                                n = 1;
237                        } else if (n) {
238                                *pp++ = cp;
239                                n = 0;
240                                havesearch = 1;
241                        }
242                }
243                /* null terminate last domain if there are excess */
244                while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
245                        cp++;
246                *cp = '\0';
247                *pp++ = 0;
248        }
249
250#define MATCH(line, name) \
251        (!strncmp(line, name, sizeof(name) - 1) && \
252        (line[sizeof(name) - 1] == ' ' || \
253         line[sizeof(name) - 1] == '\t'))
254
255        if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
256            /* read the config file */
257            while (fgets(buf, sizeof(buf), fp) != NULL) {
258                /* skip comments */
259                if (*buf == ';' || *buf == '#')
260                        continue;
261                /* read default domain name */
262                if (MATCH(buf, "domain")) {
263                    if (haveenv)        /* skip if have from environ */
264                            continue;
265                    cp = buf + sizeof("domain") - 1;
266                    while (*cp == ' ' || *cp == '\t')
267                            cp++;
268                    if ((*cp == '\0') || (*cp == '\n'))
269                            continue;
270                    strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
271                    if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
272                            *cp = '\0';
273                    havesearch = 0;
274                    continue;
275                }
276                /* set search list */
277                if (MATCH(buf, "search")) {
278                    if (haveenv)        /* skip if have from environ */
279                            continue;
280                    cp = buf + sizeof("search") - 1;
281                    while (*cp == ' ' || *cp == '\t')
282                            cp++;
283                    if ((*cp == '\0') || (*cp == '\n'))
284                            continue;
285                    strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
286                    if ((cp = strchr(_res.defdname, '\n')) != NULL)
287                            *cp = '\0';
288                    /*
289                     * Set search list to be blank-separated strings
290                     * on rest of line.
291                     */
292                    cp = _res.defdname;
293                    pp = _res.dnsrch;
294                    *pp++ = cp;
295                    for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
296                            if (*cp == ' ' || *cp == '\t') {
297                                    *cp = 0;
298                                    n = 1;
299                            } else if (n) {
300                                    *pp++ = cp;
301                                    n = 0;
302                            }
303                    }
304                    /* null terminate last domain if there are excess */
305                    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
306                            cp++;
307                    *cp = '\0';
308                    *pp++ = 0;
309                    havesearch = 1;
310                    continue;
311                }
312                /* read nameservers to query */
313                if (MATCH(buf, "nameserver") && nserv < MAXNS) {
314                    struct in_addr a;
315
316                    cp = buf + sizeof("nameserver") - 1;
317                    while (*cp == ' ' || *cp == '\t')
318                        cp++;
319                    if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
320                        _res.nsaddr_list[nserv].sin_addr = a;
321                        _res.nsaddr_list[nserv].sin_family = AF_INET;
322                        _res.nsaddr_list[nserv].sin_port =
323                                htons(NAMESERVER_PORT);
324                        nserv++;
325                    }
326                    continue;
327                }
328#ifdef RESOLVSORT
329                if (MATCH(buf, "sortlist")) {
330                    struct in_addr a;
331
332                    cp = buf + sizeof("sortlist") - 1;
333                    while (nsort < MAXRESOLVSORT) {
334                        while (*cp == ' ' || *cp == '\t')
335                            cp++;
336                        if (*cp == '\0' || *cp == '\n' || *cp == ';')
337                            break;
338                        net = cp;
339                        while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
340                               isascii((int)*cp) && !isspace((int)*cp))
341                                cp++;
342                        n = *cp;
343                        *cp = 0;
344                        if (inet_aton(net, &a)) {
345                            _res.sort_list[nsort].addr = a;
346                            if (ISSORTMASK(n)) {
347                                *cp++ = n;
348                                net = cp;
349                                while (*cp && *cp != ';' &&
350                                        isascii((int)*cp) && !isspace((int)*cp))
351                                    cp++;
352                                n = *cp;
353                                *cp = 0;
354                                if (inet_aton(net, &a)) {
355                                    _res.sort_list[nsort].mask = a.s_addr;
356                                } else {
357                                    _res.sort_list[nsort].mask =
358                                        net_mask(_res.sort_list[nsort].addr);
359                                }
360                            } else {
361                                _res.sort_list[nsort].mask =
362                                    net_mask(_res.sort_list[nsort].addr);
363                            }
364                            nsort++;
365                        }
366                        *cp = n;
367                    }
368                    continue;
369                }
370#endif
371                if (MATCH(buf, "options")) {
372                    res_setoptions(buf + sizeof("options") - 1, "conf");
373                    continue;
374                }
375            }
376            if (nserv > 1)
377                _res.nscount = nserv;
378#ifdef RESOLVSORT
379            _res.nsort = nsort;
380#endif
381            (void) fclose(fp);
382        }
383        if (_res.defdname[0] == 0 &&
384            gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
385            (cp = strchr(buf, '.')) != NULL)
386                strcpy(_res.defdname, cp + 1);
387
388        /* find components of local domain that might be searched */
389        if (havesearch == 0) {
390                pp = _res.dnsrch;
391                *pp++ = _res.defdname;
392                *pp = NULL;
393
394#ifndef RFC1535
395                dots = 0;
396                for (cp = _res.defdname; *cp; cp++)
397                        dots += (*cp == '.');
398
399                cp = _res.defdname;
400                while (pp < _res.dnsrch + MAXDFLSRCH) {
401                        if (dots < LOCALDOMAINPARTS)
402                                break;
403                        cp = strchr(cp, '.') + 1;    /* we know there is one */
404                        *pp++ = cp;
405                        dots--;
406                }
407                *pp = NULL;
408#ifdef DEBUG
409                if (_res.options & RES_DEBUG) {
410                        printf(";; res_init()... default dnsrch list:\n");
411                        for (pp = _res.dnsrch; *pp; pp++)
412                                printf(";;\t%s\n", *pp);
413                        printf(";;\t..END..\n");
414                }
415#endif
416#endif /* !RFC1535 */
417        }
418
419        if ((cp = getenv("RES_OPTIONS")) != NULL)
420                res_setoptions(cp, "env");
421        _res.options |= RES_INIT;
422        return (0);
423}
424
425static void
426res_setoptions(options, source)
427        char *options, *source;
428{
429        char *cp = options;
430        int i;
431
432#ifdef DEBUG
433        if (_res.options & RES_DEBUG)
434                printf(";; res_setoptions(\"%s\", \"%s\")...\n",
435                       options, source);
436#endif
437        while (*cp) {
438                /* skip leading and inner runs of spaces */
439                while (*cp == ' ' || *cp == '\t')
440                        cp++;
441                /* search for and process individual options */
442                if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
443                        i = atoi(cp + sizeof("ndots:") - 1);
444                        if (i <= RES_MAXNDOTS)
445                                _res.ndots = i;
446                        else
447                                _res.ndots = RES_MAXNDOTS;
448#ifdef DEBUG
449                        if (_res.options & RES_DEBUG)
450                                printf(";;\tndots=%d\n", _res.ndots);
451#endif
452                } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
453#ifdef DEBUG
454                        if (!(_res.options & RES_DEBUG)) {
455                                printf(";; res_setoptions(\"%s\", \"%s\")..\n",
456                                       options, source);
457                                _res.options |= RES_DEBUG;
458                        }
459                        printf(";;\tdebug\n");
460#endif
461                } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
462                        _res.options |= RES_USE_INET6;
463                } else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1)) {
464                        _res.options |= RES_NOTLDQUERY;
465                } else {
466                        /* XXX - print a warning here? */
467                }
468                /* skip to next run of spaces */
469                while (*cp && *cp != ' ' && *cp != '\t')
470                        cp++;
471        }
472}
473
474#ifdef RESOLVSORT
475/* XXX - should really support CIDR which means explicit masks always. */
476static u_int32_t
477net_mask(in)            /* XXX - should really use system's version of this */
478        struct in_addr in;
479{
480        register u_int32_t i = ntohl(in.s_addr);
481
482        if (IN_CLASSA(i))
483                return (htonl(IN_CLASSA_NET));
484        else if (IN_CLASSB(i))
485                return (htonl(IN_CLASSB_NET));
486        return (htonl(IN_CLASSC_NET));
487}
488#endif
489
490u_int
491res_randomid()
492{
493        struct timeval now;
494
495        gettimeofday(&now, NULL);
496        return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
497}
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